Gemmological and Spectroscopic Characteristics of Haüyne from Germany

Haüyne is a rare gemstone in sodalite group with unique bright blue colour.The authors undertook a series of tests and analyses on gem-quality haüyne samples from Eifel district in Germany with the help of conventional gemmological tests,energy dispersive X-ray fluorescence spectroscopy,UV-Vis spectrophotometer,Fourier transform infrared spectrometer and Raman spectroscopy. Conventional gemmological tests show that the refractive index of haiyne is around 1. 50 and specific gravity ranges from 2.42 to 2. 48. Weak absorption band at orange region can be observed by a hand spectroscope. Under long-wave ultraviolet light the samples show orange fluorescence of medium to strong intensity, the lighter the colour, the brighter the fluorescence, and vice versa. It shows that in haiyne there are many point-like, needle like inclusions, rounded crystals and stress fractures around,fingerprint inclusions and healed fractures observed by microscope.